Lubricating oil composition containing pour point depressant



' Patented July 11, 1950 LUBRICA'IING OIL COMPOSITION CONTAIN- ING POUR POINT DEPRESSANT Eugene Lieber, Chicago, Ill., and Edward P. Cashman,

Bayonne, N..J., assignors to Standard Oil Development Company, a corporation of Delaware No Drawing. Application June 20, 1946,

- Serial No. 678,167

12 Claims. (Cl. 252-463) This invention relates to the preparation of a novel mineral oil composition which flows at lower temperatures than the oil base stock from which it is prepared. More particularly, the invention relates to the preparation of a lubricatmg oil composition containing an additive which gives the lubricant an unexpectedly low stable pour point.

It has been known for sometime that pour depressors for waxy mineral lubricating oils can be made by a Friedel-Crafts condensation of long chain aliphatic compounds such as chlorinated paraflin wax with aromatic compounds such as naphthalene. Small amounts, e. g., 0.1% to 2.0%, of such pour depressors may lower the A. S. T. M. pour point of a waxy mineral lubricating oil, for example, from +30 F. down to a temperature ranging from F. to as low as 35 F. r

or lower, depending upon the particular type of oil used, the nature and method of preparation of the pour depressor, and the concentration in which the latter is used. Although it has been found that such a pour depressor may reduce the A. S. T. M. pour point to 30 F. or more, the blend may still have a 40 or 50 higher stable pour point, of the order of +l0 or F., as determined by the Test V" pour stability test, described in Oil and Gas Journal, vol. 42, No. 7, pp. 103-106 (June 24, 1943). In this test the samples of oil are subjected to a series of temperature cycles ranging from F. to higher levels to simulate the rise and fall of temperature during a winter season. This means that when a blend of waxy lubricating oil containing a small amount of pour depressor is stored in the winter in a place where it is subject to the fluctuation of the normal atmospheric temperature, the repeated cycles of alternate warming and cooling will permit the oil blend to become solid at temperatures of 20 or or even 50 F. higher than the A. S. T. M. pour point of such blends.

It has now been found, in accordance with present invention, that if the above-described condensation product of a long chain aliphatic compound with an aromatic compound is modifled by further reacting the same with a halide, oxyhalide or sulfohalide of phosphorus, surprisingly stable pour points are produced, and in fact the pour point can be so stabilized that solidification of the oil will not result at temperatures as low as 20 F.. even though a similar oil containing the unmodified pour depressor would solidify at temperatures as high as +4 to +14 F. after subjecting the same to two or more cycles of rising and falling temperature.

The alkyl-aromatic type pour depressor may be the prepared by any of the large number of methods known to the art, one of the earliest of which was disclosed in U. S. Patent 1,815,022. In making such alkyl-aromatic condensation product, the aromatic compound to be used may be an aromatic hydrocarbon such as naphthalene, diphenyl, anthracene, etc. The long chain aliphatic compound is preferably a material such as parafiin wax which is chlorinated to a chlorine content of about 10 to about 20%. Alternatively, such chlorinated wax or equivalent material may be dehydrochlorinated to produce corresponding olefins andthe olefins may be condensed with the aromatic compound. Other long chain aliphatic compounds may be used, preferably having more than ten aliphatic carbon atoms, such as stearic acid, stearyl chloride, octadecyl alcohol, cetyl a1- cohol, etc. These condensation products are preferably made by the use of a Friedel-Crafts type catalyst such as aluminum chloride, zinc chloride, anhydrous hydrogen fluoride, etc., preferably in the presence of an inert solvent such as 0.05 to 5 volumes, preferably 0.1 to 1.0 volume, of a highly refined kerosene, heavy naphtha, or tetrachlorethane, per volume of mixed reactant.

The reaction is conducted at a temperature ranging from room temperature up to about 200 F., preferably from to 150 F. The reaction is followed by hydrolysis of the catalyst by washing with water, alcohol, or alcoholic caustic, removal of the metal hydroxide by-product by filtration or otherwise, and distillation of the reaction product under reduced pressure at a temperature up t about 500 or 600 F. to obtain the high'molecular weight condensation product as a distillation residue.

The class of phosphorusand halogen-containing compounds which may advantageously be reacted with the above-described alkyl-aromatic type pour depressor may be defined by the formula P(Y)m(X)n. where Y is oxygen or sulfur, X is a halogen, preferably chlorine, m is 0 or 1, and n is 3 or 5. Either the monomeric or polymeric forms of these compounds may be used. Preferred examples of suitable compounds are phosphorus trichloride, phosphorus pentachloride, phosphorus oxychloride and phosphorus sulfochloride.

When modifying the aliphatic-aromatic condensation product in accordance with this invention it is preferred to employ from 2 to 20 parts by weight oi. the phosphorus compound for each parts by weight of the aliphatic compound employed in the condensation reaction. The reaction of the phosphorus compound with the condensation product may advantageously be conducted at approximately the same temperature at which the original condensation reaction took place, and often a somewhat lower temperature may be employed.

The reaction of the phosphorus and halogen compound with the aliphatic-aromatic condensation product may be conducted by carrying out the reaction with the finished condensation product, as obtained, for example, by the method described above; but it has been found advantageous to add the phosphorus compound directly to the reaction mixture in which the condensation reaction is taking place prior to the hydrolysis step, and then to continue the reaction process as described above, providing additional catalyst if necessary. In this manner it is necessary to hydrolyze the catalyst only once, and duplication of other finishing steps may be avoided.

The 011 base stocks into which the additive described above is incorporated are preferably waxy mineral lubricating oils such as a paraflinic lubrieating oil base stock or a mixed base, which may have been subjected to any one or more of the commonly used refining steps, such as distillation, solvent extraction, acid treating, clay treating, etc., as well as partial dewaxing. Such oil base stock may either be one which is within the known lubricating oil viscosity range, or it may be an oil of much lower viscosity, such as one which is used in the preparation of hydraulic oils, etc., and which may have a viscosity as low as 40 seconds Saybolt at 100 F.

In employing the pour depressant of the present invention it has been found desirable to use the product in the proportion of about 0.02% to 3% or so, preferably about 0.1% to 2.0%, based on the lubricating 01] base stock.

The desirable results obtained by the'use of the modified aliphatic-aromatic pour depressor of the present invention and detailed methods of preparing such product are given in the following examples, which are to be considered as illustrative only and not as limiting the scope of the invention in any way.

Example 1 (A) A pour depressor was produced by condensing 100 parts by weight 01 chloro-parafiln wax (containing 14.5% chlorine) with 13% parts by weight of naphthalene, using 2 parts by weight of A1013 as the catalyst. The reaction was conducted at a temperature of about 125 F. in the presence of parts of tetrachlorethane as solvent. After a reaction time of 4 hours the catalyst was hydrolyzed by the addition of an excess of isopropyl alcohol and aqueous caustic soda, and the aluminum hydroxide produced by the hydrolysis was removed. The product was then distilled to remove the diluent and the unreacted constituent to a temperature of 600 F. with fire and steam.

(B) A condensation reaction was conducted in accordance with the detafls set forth in (A), except that 3 hours after the beginning of the reaction of the'naphthalene with the chloro-' parafiin, 6 parts by weight of PC15 dissolved in 67 parts of tetrachlorethane was added to the reaction mixture over a period of minutes. Reaction with the P015 took place quite vigorously. After the addition of the PC15 the reaction was continued for an additional 30 minutes, making not was purified and recovered as previously described in (A).

1 a total of 4 hours of reaction time. The prod- Example 2 The product obtained in Example 1(B) was tested by blending the same in a waxy lubricating oil having an initial pour point 01' +25 F.- and testing the resulting blends to determine the A. S. T. M. pour point. The following results were obtained:

Example 3 The pour stability properties of the products of Examples 1(A) and 1( B) were tested in accordance with Test V, previously described in this specification, using blends containing 0.25% of each additive in a base oil which was a solvent extracted Mid-Continent lubricating oil fraction containing 3 of a Pennsylvania bright stock and having a Saybolt viscosity at F. of 148 and a viscosity at 210 F. of 42.7, and an A. s. 'r. M. pour point of +25" F. The results show the "solid point according to Test V," as measured in the second and third cycles of the test, which represent a temperature drop from +30 F. to 20 F. and from +20 F, to 20 F., the solid point" signifying the temperature at which the oil becomes solid during the course of radual fall in temperature. The results obtained were as follows:

Test V Solid Point,

F. Pour Depressor Second Third Cycle Cycle Product of Example l(A) +14 -l9 Product of Example 1(B) -1l 1 DNBS I signifies did not become solid."

It is not intended that this invention be limited to the specific examples which have been given merely for the sake of illustration, but only by the appended claims in which it is intended to claim all novelty inherent in the invention and all modifications coming within the scope and spirit of the invention.

We claim:

1. A lubricating composition consisting essentially of a major proportion of a waxy mineral lubricating oil and a pour depressing amount of a product obtained by reacting a long chain chlorinated aliphatic compound having at least 10 carbon atoms with naphthalene in the presence of a, Friedel-Crafts catahlst at a temperature of room temperature to about 200 F. and further reacting the product thus formed at about the same temperature range in the presence of a Friedel-Crafts catalyst with a phosphorusand halogen-containing compound having the empirical formula P(Y) 910!) n, where X is a halogen, Y is a member of the class consisting of oxygen and sulfur, m is a number from 0 to 1, and n is an odd number from 3 to 5.

2. A composition according to claim 1 in which the phosphorusand halogen-containing compound is a phosphorus chloride.

3. A lubricating composition consisting essentially of a major proportion of a waxy mineral lubricating oil and a pour depressing amount of a product obtained by condensing chlorinated paraflln wax with naphthalene in the presence of a Friedel-Crafts catalyst at a temperature from about 90 F. to about 150 F. and then condensing the product thus formed at about the same temperature range in the presence of a Friedel-Crafts catalyst with a phosphorusand halogen-containing compound having the empirical formula P(Y) MK)", where X is a halogen, Y is a member of the class consisting of oxygen and sulfur, m is a number from to 1, and n is an odd number from 3 to 5.

4. A composition according to claim 3 in which the phosphorusand halogen-containing compound is a phosphorus chloride.

5. A composition according to claim 3 in which the phosphorusand halogen-containing compound is prosphorus pentachloride.

6. A composition according to claim 3 in which the phosphorusand halogen-containing compound is phosphorus oxychloride.

7. A lubricating composition comprising a major proportion of a waxy mineral lubricating oil and about 0.1 to about 2.0% by weight of the product obtained by condensing about 100 parts by weight of parafiln chlorinated to about 14.5% chlorine with 13.5 parts by weight of naphthalene in the presence of about 2 parts by weight of aluminum chloride at a temperature of about 125 F. and in the presence of a solvent, and further condensing the reaction mass with about 6 parts by weight of phosphorus pentachloride at about 125 F. in the presence of a Friedel-Crafts catalyst.

8. As a new composition of matter, a product obtained by reacting a long chain chlorinated aliphatic compound having at least carbon atoms with naphthalene in the presence of a Friedel-Crafts catalyst at a temperature from room temperature to about 200 F. and further reacting the reaction mass at about the same temperature range in the presence of a Friedel- Crafts catalyst with a phosphorusand halogencontaining compound having the empirical formula P(Y)m(X) a, where X is a halogen, Y is a member of the class consisting of oxygen and odd number from 3 to 5.

9. As a new composition of matter, the product 7 obtained by condensing chlorinated paraflln was Q with naphthalene in the presence of aluminum chloride at a temperature of'from F. to 150 F. and further condensing the reaction mass with phosphorus pentachloride at about the same temperature range in the presence of a Friedel-Crafta catalyst.

10. As a new composition of matter, a product obtained by condensing about parts by weight of paraflin chlorinated to about 14.5% chlorine with about 13.5 parts by weight of naphthalene in the presence of about 2 parts by weight of aluminum chloride .at a temperature of about. F. and in the presence of a solvent, and further' condensing the product thus formed with about 6 parts by weight of phosphorus pentachloride at about 125 F. in the presence of a Friedel- Crafts catalyst.

11. A method of preparing a composition suitable'for use as a pour depressing agent for mineral oils which comprises condensing chlorinated parailln wax containing about 10% to about 20% of chlorine with naphthalene in the presence of a Friedel-Crafts catalyst at about 90 F. to about F. and further condensing the'reaction mass in the presence of a Friedel-Crafts catalyst with phosphorus pentachloride at a temperature at about 90 F. to about 150 F.

12. A method of preparing a composition suitable for use as a pour depressing agent for mineral oils which comprises condensing about 100 parts by weight of paraflln chlorinated to a chicrine content of about 14.5% by weight with about 13.5 parts by weight of naphthalene in the presence of about 2 parts by weight of aluminum chloride at a temperature of about 125 F. and in the presence of a solvent, and further condensing the reaction mass with about 6 parts by weight of phosphorus pentachloride at about 125 F. in the presence of aluminum chloride.

EUGENE LIEBER. EDWARD P. CASHMAN.

REFERENCES CITED The following references are of record in the tile of this patent:

UNITED STATES PATENTS Number Name Date 1,815,022 Davis' July 14, 1931 Jolly Feb. 20, 1940 2,242,260 Prutton May 20, 1941 2,246,059 Moran June 17, 1941 MaoI-aren Apr. 6, 1948 

1. A LUBRICATING COMPOSITION CONSISTING ESSENTIALLY OF A MAJOR PROPORTION OF A WAXY MINERAL LUBRICATING OIL AND A POUR DEPRESSING AMOUNT OF A PRODUCT OBTAINED BY REACTING A LONG CHAIN CHLORINATED ALIPHATIC COMPOUND HAVING AT LEAST 10 CARBON ATOMS WITH NAPHTHALENE IN THE PRESENCE OF A FRIEDEL-CRAFTS CATALYST AT A TEMPERATURE OF ROOM TEMPERATURE TO ABOUT 200*F. AND FURTHER REACTING THE PRODUCT THUS FORMED AT ABOUT THE SAME TEMPERATURE RANGE IN THE PRESENCE OF A FRIEDEL-CRAFTS CATALYST WITH A PHOSPHORUS- AND HALOGEN-CONTAINING COMPOUND HAVING THE EMPIRICAL FORMULA P(Y)M,(X)N, WHERE X IS A HALOGEN, Y IS A MEMBER OF THE CLASS CONSISTING OF OXYGEN AND SULFUR, M IS A NUMBER FROM 0 TO 1, AND N IS AN ODD NUMBER FROM 3 TO
 5. 